Spring sash counterbalance



p 1952 E. E. FOSTER 2,609,193

SPRING SASH COUNTERBALANCE Filed April 30, 1947 5 Sheets-Sheet l Eda/(1051 60 awe ms p 1952 I E. E. FOSTER 2,609,193

spams SASH COUNTERBALANCE Filed April 30, 1947 3 Sheets-Sheet 2 Sept. 1952 E. E. FOSTER 2,609,193

' SPRING SASH COUNTERBALANCE Filed April 30, 1947 3 Sheets-Sheet 3 Edwin) E lfim'ien Patented Sept. 2, i952 SPRING SASH COUNTERBALANCE Edwin E. Foster, Austin, Tex., assignor, by mesne assignments, to Eastern Metals Research 00., 7 Inc., New York, N. Y., a corporation of New York Application April 30, 1947, Serial'No. 744,809

' 3 Claims. (01. 267-1 J .This invention relates to a Window or. door counter-balance and more particularly to a coiled sprin which by its coiling action actsto counterbalance a window sash and the like.

.It is an object of the invention to provide a spring. ribbonwhich is tensioned to wind itself intoa coil and which acts to counter-balance the window sash. A further object of the invention resides in a tightly wound coil which: has one endsecured to a spool or center but rotatably mounted in a window sash and the other end secured to a window frame. Another object of the invention resides in the particular construction of :the spring ribbon or band which is tapered from one end to the other to thus act as a compensator during the entire coiling or uncoiling action of the spring. It is therefore an object of the invention to provide a window sash with a tapered ribbon spring to act as a constant counter-balance force for the window sash at all locations of the window. Another object resides in the provision of aispring' which is normally tightlywound into a-spiralcoil and unwinds as a spring. 1

A still further object resides in a coiled spring mounted to rotate without a spool or shaft in a cut-out portion in the edge of the window stile. Another object resides in a spring with a uniformwidth and a uniform uncoiling or coiling force throughout all the variouscoils irrespective of the radii of the coils. l i

Further objects will be apparentfrom the followingdescription when .considered in connection with the accompanying drawing in which,

Fig. 1 is a side elevation of the lower left portion of a window and a part of the window frame with parts broken away and in section,

1 Fig. 2 is afront elevation of the-complete window. and frame with part of a window sash broken away,

Fi 3 is a side elevation partly in section of a portion of an automobile window with the counter-balance applied thereto,

Fig. 4. is a cross-section taken on line 4-4 of Fig. 3,

.. Fig. 5 is a side elevation of the spring and its spool in theextended position, 1 1

Fig. 6 is a side elevation of the lower left portion of a window and window frame with parts broken away and in section,

'I is an end elevation of the window sash Qf Fig. 6,

Fig. 8 .is a diagrammatic view, and

:Figs. 9 and 10 are front and side front elevations respectively ofa modified spring.

I. The invention may be applied to any sliding window or door but as an example the 7' drawing shows a .window with an upper sash l and a lower sash 2 slidably mounted in aframe 3. To clearly show the invention the usual guidestrips on the frame have been omitted. Each sash has a rectangular cut out portion preferably at each end as at 4 to receive a U-shaped metal frame 5' acting asabearing for a spool 6 A ribbon spring 7 is secured at one end 8 in aslot in the spool 6 and the other end 9 is secured to the window frame by a nail ID or any other suitable fastening. The spring I is tapered as shown in Fig. 5. As seen from Figs. 1 and 2 the sash balance is practically invisible, that is it cannot be seen when the sash is loweredor in its raised position, except, of course, the tip end of the tape where the nail H) or screw fastens the spring tape 1 to the frame 3. Eitherone or two (preferably two) balances areused to a sash, and on unusually heavy sashes additional balances can be installed directly above the one shown, and

the steel'spring ribbon pinned t the frame with the same screw or nail Ill.

' Unlike the ordinary clock spring type, which consists of a clock spring within a drum and a cable or ribbon wrapped around the drum, this balance uses a ribbon spring, the normal position of which is a tightly wound coil attached to the center hub or spool 15. The free end 9 of the spring ribbon is unwound and fastenedto the framejust above the top of the sash when the sash is down. The spool, which is preferably encased in a squar box, or the U-shaped frame 5, is recessed into the lower corner of the stile of the sash.

Figure 2 shows the sashin its extreme closed position and the steel ribbon has been unwound, since the free end is pinned to the frame and the spool is allowed to turn on its axis or pin in the frame. It will be noted in Fig. 5 that the spring ribbon is proportionately wide at thetop and gradually tapered to a smaller width at "the bottom. This acts as a compensator, since if the ribbon spring were the same width throughout its full length it would become stronger towards the bottom of its stroke, but with the proper amount of taper in the width (or thickness), this spring acts as a perfect balance throughout its entire stroke. The ribbon is preferably fastened to the spool, and this type of spring would, of

course, need to be wound in this position'while spool than the one on which it was originally spring in response to a force applied to the outer end of the spring.

EDWIN E. FOSTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Number Name Date Goldsmith et a1. 1 Apr. 12, 1927 Fredericks May 10, 1927 Gettnei' Aug. 30, 1927 Kreissig Feb. 4, 1930 Vallee Aug. 18, 1931 Fornelius Oct. 16, 1934 Hope Feb. 17, 1942 Piron June 12, 1945 FOREIGN PATENTS Country Date Switzerland -1 May 16, 1922 

